For many years, supermarkets packed one's purchased groceries in paper bags. These bags were commonly made of medium to heavy weight brown paper and had a flat bottom. Once properly packed, these bags could be easilY carried, and if placed upright on a flat surface, remain stable in this upright position. The bag's stability in the upright position greatly facilitated transporting of filled bags that were placed within a car's trunk or on a car's floor or seat.
In an effort to reduce costs and to make the bag easier to carry, supermarkets now commonly use a specially designed plastic bag for the bagging of groceries. The bag includes a pair of shaped handle portions at its top and a semi-flat bottom. To carry a bag of this type, one merely has to place one's fingers through the handles and lift. The old style paper bags required bottom support during carrying.
However, the new type of bags do suffer one great drawback. When packed with groceries and placed on a flat surface, the bag is unstable in its upright position. The user often has to lodge the bag in place either during or after positioning it within a car. Without external support, the bag falls over during a car's turning or braking movements. Due to this inconvenience, many consumers request the supermarket to bag their groceries in the old-style paper bags. This increases the supermarket's costs and forces the consumer to use a bag that is more awkward to carry.